1. Field of the invention:
This invention relates to an improved contact pin which, for example, is disposed in an apparatus for an IC card to be brought into contact with a terminal formed on a circuit pattern on an inserted IC card.
2. Description of the prior art:
An apparatus into which an IC card is inserted has a plurality of contact pins therein which are brought into contact with terminals formed on a circuit pattern on the inserted IC card so that an electric signal is transmitted between the IC card and the apparatus.
FIG. 5 shows an apparatus having conventional contact pins in which an IC card is used, illustrating how the IC card and the conventional contact pins are brought into contact with each other.
In an IC card 10 which is to be used in an apparatus 12, a circuit pattern is formed, and a plurality of terminals 11 are exposed on the upper surface of the IC card 10. The apparatus 12 has a recess 13 into which the IC card 10 is to be inserted. Above the recess 13, a base 16 which can move vertically is disposed, and a plurality of contact pins 14 are attached to the bottom face of the base 16. Each of the contact pins 14 are elastically pushed down by a coil spring 15.
When the IC card 10 is used, the IC card 10 is inserted into the recess 13 of the apparatus 12 in the direction of arrow A. The base 16 then moves down in the direction of arrow B, and end tips 14a of the contact pins 14 come into contact with the surfaces of the terminals 11 formed on the inserted IC card 10, as shown in FIG. 5.
In the above-mentioned structure, the contact pins 14 are made of metal, and the end tips 14a of the contact pins 14 are sharpened so as to assure the excellent contact between the end tips 14a and the surfaces of the terminals 11. Therefore, as the number of insertions of the IC card 10 into the apparatus 12 increases, and accordingly the number of contacts between the contact pins 14 and the terminals 11 increases, the surface of each terminal 11 is gradually damaged in the region 11a, at which the end tip 14a of the contact pin 14 comes into contact with the terminal 11, thereby forming a concavity in the region 11a, resulting in that an IC card having such a damaged terminal becomes useless.